This process is currently performed manually by several operators provided with metal bars which they use as a lever, pulling and shifting the crosstie until its correct definitive position. They also manually check with a square the perpendicularity of each of the crossties with respect to the rails and its correct distance to the previous crosstie.
This process performed in this manner is extremely slow and imprecise. In addition, given the large weight of the crossties, it is a physical risk for the operators, and causes a large number of injuries throughout the year.